Cannabidiol Anticonvulsant Effects Against Lithium-Pilocarpine-Induced Status Epilepticus in Male Rats Are Mediated by Neuroinflammation Modulation and Cannabinoids 1 (CB1), But Not CB2 and GABAA Receptors.

Background: Status epilepticus (SE) is a series of seizures that can lead to serious neurological damages. Cannabidiol (CBD) is extracted from the cannabis plant, which has been approved as an antiseizure medication. This study aimed to determine the efficacy of various doses of CBD on lithium-pilocarpine-induced SE in rats and possible involvement of multiple pharmacological pathways. We hypothesized that cannabinoid receptors type 1 (CB1) and CB2, as well as GABAA receptors, might have important roles in the anticonvulsant effects of CBD against SE by its anti-inflammatory effects. Methods: SE was induced by intraperitoneal (i.p.) injection of lithium (127 mg/kg, i.p.) and pilocarpine (60 mg/kg, i.p., 20 h after lithium). Forty-two male rats were divided into seven groups (including control and sham groups), and the treated groups received different doses of CBD (1, 3, 5, 10, and 25 mg/kg, i.p.). SE score was recorded over the next 2 h following pilocarpine injection. Then, we measured the levels of pro-inflammatory cytokines, including interleukin (IL)-lß and tumor necrosis factor (TNF)-α, using ELISA kits. Also we analyzed the expression of CB1, CB2, and GABAA receptors using the Western blot technique. Results: CBD at 5 mg/kg significantly reduced Racine's scale and duration of seizures, and increased the onset time of seizure. Moreover, CBD 5 mg/kg caused significant reductions in the elevated levels of IL-lß and TNF-α, as well as a significant increase in the decreased level of CB1 receptor expression compared to the control group. In other word, CBD reverted the effects of SE in terms of neuroinflammation and CB1 receptor. Based on the obtained results, CBD was not able to restore the declined levels of CB2 or GABAA receptors. Conclusion: Our study found anticonvulsant effects of CBD on the SE rat model induced by lithium-pilocarpine with probable involvement of CB1 receptors and anti-inflammatory effects by reducing IL-1ß and TNF-α markers independent of CB2 and GABAA receptors.

Potential use of angiotensin receptor blockers in skin pathologies.

Renin-angiotensin system (RAS) components such as angiotensin II, angiotensin receptors (AT1R and AT2R), and angiotensin-converting enzyme (ACE) are expressed in different cell types of the skin. Through AT1R, angiotensin II increases proinflammatory cytokines contributing to fibrosis, angiogenesis, proliferation, and migration of immune cells to the skin. In contrast, AT2R suppresses the effects mentioned above. Many studies show that angiotensin receptor blockers (ARBs) and angiotensin-converting enzymes (ACEi) reduce the proinflammatory cytokines and fibrogenic factors including transforming growth factor ß (TGF-ß), Connective tissue growth factor (CTGF), and IL-6. This review article provides a detailed research study on the implications of ARBs in wound healing, hypertrophic scar, and keloids. We further discuss the therapeutic potentials of ARBs in autoimmune and autoinflammatory skin diseases and cancer, given their anti-fibrotic and anti-inflammatory effects.

Cannabidiol interacts with the FXR/Nrf2 pathway and changes the CB1/CB2 receptors ratio in gentamicin-induced kidney injury in rats.

Objectives: Gentamicin-induced nephrotoxicity was used as an experimental model of kidney disease. The present study was performed to assess the therapeutic role of cannabidiol (CBD) against gentamicin-induced renal damage. Materials and Methods: Forty two male Wistar rats were randomly allocated into 6 groups (n=7), including: (1) Control, (2) Vehicle, (3) Gentamicin-treated group (100 mg/kg/day) for 10 days (GM), (4-6) 3 Gentamicin-CBD-treated groups (2.5, 5, and 10 mg/kg/day) for 10 days (GM+CBD2.5, GM+CBD5, GM+CBD10). Serum levels of BUN and Cr, renal histology as well as real-time qRT-PCR were used to investigate the pattern of changes at different levels. Results: Gentamicin increased serum BUN and Cr (P<0.001), down-regulation of FXR (P<0.001), SOD (P<0.05) and up-regulation of CB1 receptor mRNA (P<0.01). Compared to the control group, CBD at 5 decreased (P<0.05) and at 10 mg/kg/day increased the expression of FXR (P<0.05). Nrf2 expression in CBD groups was increased (P<0.001 vs. GM). The expression of TNF-α compared to the control and GM groups, was significantly increased in CBD2.5 (P<0.01) and CBD10 (P<0.05). Compared to the control, CBD at 2.5 (P<0.01), 5 (P<0.001) and 10 (P<0.001) mg/kg/day significantly increased the expression of CB1R. Up-regulation of CB1R in the GM+CBD5, was significantly higher (P<0.05) than the GM group. Compared to the control group, the most significant increase in CB2 receptor expression was observed at CBD10 (P<0.05). Conclusion: CBD particularly at 10 mg/kg/day might be of significant therapeutic benefit against such renal complications. Activating the FXR/Nrf2 pathway and counteracting the deleterious effects of CB1 receptors via CB2 receptors scale-up could be part of the protective mechanisms of CBD.

Cannabidiol Improves Random-Pattern Skin Flap Survival in Rats: Involvement of Cannabinoid Type-2 Receptors.

BACKGROUND: One of the major complications associated with random-pattern skin flaps is distal necrosis. Cannabidiol (CBD) has recently gained much attention as a therapeutic anti-inflammatory agent. We aimed to evaluate the efficacy of CBD on the random-pattern skin flap survival (SFS) in rats and to explore the possible involvement of cannabinoid type-2 (CB2) receptors. METHODS: In this controlled experimental study, we randomly divided male Wistar rats into seven study groups (six rats each). We performed a random-pattern skin flap model in each rat following pretreatment with vehicle (control) or multiple doses of CBD (0.3, 1, 5, or 10 mg/kg). In a separate group, we injected SR144528 (2 mg/kg), a high affinity and selective CB2 inverse agonist, before the most effective dose of CBD (1 mg/kg). A sham nontreated and nonoperated group was also included. Seven days after surgeries, the percentage of necrotic area (PNA) was calculated. Histopathological microscopy, CB2 expression level, and interleukin (IL)-1ß and tumor necrosis factor (TNF)-α concentrations were also investigated in the flap tissue samples. RESULTS: A PNA of 72.7 ± 7.5 (95% confidence interval [CI]: 64.8-80.6) was captured in the control group. Following treatment with CBD 0.3, 1, 5, and 10 mg/kg, a dose-dependent effect was observed with PNAs of 51.0 ± 10.0 (95% CI: 40.5-61.5; p <0.05), 15.4 ± 5.8 (95% CI: 9.3-21.5; p <0.001), 37.1 ± 10.2 (95% CI: 26.3-47.8; p <0.001), and 46.4 ± 14.0 (95% CI: 31.7-61.1; p <0.001), respectively. Histopathologically, tissues enhanced significantly. Besides, CB2 expression surged remarkably, IL-1ß and TNF-α concentrations decreased considerably after treatment with CBD of 1 mg/kg compared with the control (p <0.05 and <0.001, respectively). Administering SR144528 reversed the favorable effects of CBD of 1 mg/kg, both macroscopically and microscopically. CONCLUSION: Pretreatment with CBD of 1 mg/kg improved SFS considerably in rats and exerted desirable anti-inflammatory effects which were possibly mediated by CB2 receptors.

Biliary cirrhosis-induced cardiac abnormality in rats: Interaction between Farnesoid-X-activated receptors and the cardiac uncoupling proteins 2 and 3.

Objectives: This study aimed to evaluate the relationship between Farnesoid-X-activated receptors (FXR) as nuclear regulators of the antioxidant defense system as well as cardiac mitochondrial carrier proteins of UCP2 and UCP3 in cardiac damage induced by cirrhosis. Materials and Methods: Twenty-two male Wistar rats (200-250 g) were randomly divided into 3 experimental groups, including a control group (n=6), a sham-operated group (n=8), and a bile duct ligated (BDL) group (n=8). Four weeks after surgical intervention, biochemical assessment (AST, ALT, GGT, LDH, and ALP), histological observation, and molecular evaluation (FXR, UCP2, UCP3, BNP, Caspase3, and GAPDH) using real-time RT-PCR were performed. Results: Compared with the sham-operation group, the BDL group showed a significant rise in liver enzymes of AST, ALT, GGT, LDH, and ALP. Defined fibrotic and necrotic bundles and thick reticulin fibers were also found in BDL liver tissue. Besides liver morphological alterations, left ventricles of BDL ones were also associated with defined cardiomyocyte hypertrophy, myofiber vacuolization, and clear pigmentation. Findings showed a significant up-regulation of cardiac Brain Natriuretic Peptide (BNP) along with marked down-regulation in hepatic FXR, cardiac FXR, and cardiac UCP2 and UCP3. However, the expression of caspase 3 in the cardiac tissue was not affected by BDL operation during 4 weeks. Conclusion: Expression of FXR as an upstream regulator of cellular redox status, besides the non-enzymatic ROS buffering defense system of cardiac UCPs, has a pivotal role in the pathogenesis of cirrhotic-induced cardiac abnormality in rats.

Losartan ointment attenuates imiquimod-induced psoriasis-like inflammation.

BACKGROUND: Psoriasis is a chronic skin condition associated with interleukin-23/interleukin-17 (IL-23/IL-17) pathway. Recent evidence declares that angiotensin II (Ang II) induces a potent IL-17-related inflammation. Meanwhile, Losartan, an angiotensin one receptor (AT1R) antagonist, attenuates the TH17-related responses. Therefore, we investigated the possible beneficial effects of topically applied Losartan1% ointment on imiquimod (IMQ)-induced psoriasis in mice. METHOD: Psoriasis was induced in mice consecutively for five days by topical IMQ on the shaved back. The IMQ-induced psoriasis was treated via topical administration of Losartan1% twice a day. The severity of skin inflammation was evaluated employing Psoriasis Area and Severity Index (PASI) scores. Subsequently, the skin samples were assessed using Baker's scoring system, stereological studies, and biochemical assessment with real-time PCR and immunohistochemistry. RESULTS: IMQ administration induced plaque-type psoriasis and skin inflammation. We characterized psoriatic lesions by hyperkeratosis, Munro abscess, rete ridges, and marked T-cell infiltrates. IMQ significantly increased epidermal volume, mRNA expression of IL-17a, IL-23, Ang II, AT1R, and TNF-α levels compared with the Placebo group. Topical administration of Losartan1% on IMQ-induced psoriasis significantly reduced the PASI scores and alleviated the erythema and scaling. The treatment significantly decreased the psoriatic thickness and dermal T-cell infiltration. Regarding biochemical assessment, Losartan1% considerably reduced the IMQ-induced increase of IL-17a, Ang II, and AT1R expression in the skin. CONCLUSION: Topical Losartan1% significantly alleviates psoriasis by reducing AT1R and IL-17a expression. Our results introduce AT1Rs as a promising therapeutic target in psoriasis and represent a link between angiotensin and TH17-related inflammation. However, the effects of AngII-AT1R systems on IL-17 signaling need to be confirmed by further investigations.

The renin-angiotensin system in cutaneous hypertrophic scar and keloid formation.

Hypertrophic scar and keloid are two types of fibroproliferative conditions that result from excessive extracellular matrix production. The underlying pathological mechanism is not entirely clear. Activation of the renin-angiotensin system (RAS) is associated with fibrosis in various organs. RAS components including angiotensin II (Ang II), angiotensin AT1 and AT2 receptors, and angiotensin-converting enzyme (ACE) are expressed in the skin and act independently from the plasma RAS. AT1 receptors, which are usually the dominating receptor subtype, promote fibrosis and scar formation, while AT2 receptors inhibit the aforementioned AT1 receptor-coupled effects. Elevated angiotensin II (Ang II) levels acting on the AT1 receptor contribute to skin scar formation through increased expression of inflammatory factors such as interleukin-6 (IL-6), angiogenic factors such as vascular endothelial growth factor (VEGF) and fibrinogenic factors such as transforming growth factor-ß1 (TGF-ß1) and connective tissue growth factor (CTGF), while at the same time suppressing the anti-fibrotic tissue inhibitors of matrix metalloproteinase (TIMPs). First, small clinical trials have provided evidence that inhibition of the ACE/Ang II/ AT1 receptor axis may be effective in the treatment of hypertrophic scars/keloids. This review provides a detailed overview of the current literature on the RAS in skin, wound healing and scar formation and discusses the translational potential of targeting this hormonal system for treatment and prevention of hypertrophic scars and keloids.

Chitosan/PVA/Doxycycline Film and Nanofiber Accelerate Diabetic Wound Healing in a Rat Model.

In this study, we evaluated the effects of nanofiber and film polymers with doxycycline for treating a wound in a diabetic rat model. 108 male rats were divided into six groups, the control group, the diabetic control, and the groups were diabetic rats receiving different wound dressing. At the 3rd, 7th, and 14th days, macroscopic/histologic imaging and tissue sampling were performed. Tissues were analyzed for IL-1ß, TNF-α, IL-10, TIMP-1, and MMP-2 by using ELISA. Dressings of chitosan, polyvinyl alcohol, and doxycycline increased the rate of wound closure, the volume of collagen, dermal, and epidermis. In addition, it increased the number of fibroblasts and basal cell epidermis cells, vascular length, and decreased the number of neutrophil cells. Inflammatory cytokines and MMP-2 were decreased, and anti-inflammatory IL-10 and TIMP-1 were increased. It was ultimately attained that the combination of chitosan/ polyvinyl alcohol /doxycycline could be a useful dressing for the healing of diabetic wounds.

Protective effects of combined Losartan and Nilotinib on carbon tetrachloride (CCl4)-induced liver fibrosis in rats.

Tyrosine kinase inhibitors (TKIs) have been developed as therapeutic compounds for inhibiting the progression of liver fibrosis. In the present study, the simultaneous treatment of Nilotinib (TKIs) and Losartan was studied. Forty rats were divided into eight groups of fibrosis induced by carbon tetrachloride (CCl4) and therapeutics (Nilotinib, Losartan, and combination therapy). In the end, serum parameters of the liver and gene expression analysis of transforming growth factor-ß1, its receptors (TßRII), platelet-derived growth factor, its receptors (PDGFRß), matrix metalloproteinases (MMP-2 and MMP-9), tumor necrosis factor-α, cytochrome P450 2E1, and collagen1 type 1 were performed. The oxidant/antioxidant factors were also analyzed. Histopathology analysis along with α-SMA immunohistochemistry and hydroxyproline evaluation was also conducted for a more in-depth study. The overall results indicated a better therapeutic effect of co-treatment of Nilotinib-Losartan in comparison with the treatment of each of them alone. Interestingly, some gene and protein factors and fibrotic indices were reduced even to the normal levels of the control group. The results of this study suggest that co-administration of these two combinations, strengthens their anti-fibrotic properties and, due to the routine use of these compounds against AML and blood pressure, these compounds can be used with caution against human liver fibrosis.

Semi-IPN Films and Electrospun Nanofibers Based on Chitosan/PVA as an Antibacterial Wound Dressing.

The antimicrobial activity of a wound dressing is a key factor for preventing and treating wound infection. The current study evaluated the physiochemical properties and antimicrobial activities of semi-IPNs (interpenetrating polymer networks) based on chitosan/polyvinyl alcohol (PVA) films and nanofibers as candidates for wound dressings and investigated the effects of morphologies (nanofibrous mats and films), crosslinking conditions of chitosan chains (uncrosslinked and crosslinked with genipin), and the presence of antibacterial drug (doxycycline) on their physicochemical and antibacterial properties. The morphology, chemical structure, fluid uptake, water vapor transmission rate, antimicrobial activity, and doxycycline release profile were assayed using SEM, FTIR spectroscopy, swelling test, permeation test, agar diffusion antibiogram, and dissolution test, respectively. The results demonstrated that crosslinking chitosan with genipin reduced the diameter of nanofibers, fluid uptake, and drug release from both nanofiber mats and film samples. According to the results, wound dressings with film morphology have better antimicrobial activity than those with nanofiber. The chitosan/PVA/Doxycycline 1% film has the potential for use as an antimicrobial wound dressing.

Detection of Angiotensin II and AT1 Receptor Concentrations in Keloid and Hypertrophic Scar.

Background: Keloid and hypertrophic scars (HTS) are formed by excessive collagen formation. Angiotensin II, through the AT1 receptor, plays an important role in extracellular matrix production. However, less is known about angiotensin II and AT1 receptor concentrations in HTS and keloid tissues. Objective: The purpose of this study was to determine the angiotensin II and AT1 receptor concentrations in keloid, HTS, and normal skin tissues. Methods: Skin biopsy samples from patients with HTS (n=26), keloid (n=20), and normal (n=30) skin tissues were evaluated for angiotensin II and AT1 receptor concentrations by use of the enzyme-linked immunosorbent assay technique. Results: The angiotensin II concentration in patients with HTS was higher than that in the normal (P<0.0067) and keloid (P>0.9553) groups, while the AT1 receptor concentration in patients with keloid was higher than that in the HTS (P<0.0001) and normal (P<0.0048) groups. Conclusion: Angiotensin II and AT1 receptor concentrations could stimulate the formation of HTS and keloid. Angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors may be suitable compounds for the treatment of scar tissue.

Losartan ointment relieves hypertrophic scars and keloid: A pilot study.

Keloid and hypertrophic scars are two types of fibrosis caused by extracellular matrix overexpression, and angiotensin II via AT1 receptor is known to play a key role in stimulation of fibrosis. A pilot placebo controlled single blind study was carried out on patients with hypertrophic scars and keloids. A total of 37 adult volunteers were randomly assigned into losartan 5% or placebo treatment groups. The treatment was performed twice a day for three months and a 6-month follow-up. The treatment was evaluated using Vancouver scar scale method. Totally, 30 participants were analyzed (Losartan ointment n = 20; placebo ointment n = 10; seven placebo volunteers left the study because they thought the treatment was not effective for them). In the losartan group, VSS scores dropped significantly (p < 0.01) both in keloid and hypertrophic scar patients. Vascularity and pliability were significantly reduced by losartan treatment (p < 0.05). It can be concluded that losartan potassium ointment (5%) can alleviate the keloid and hypertrophic scar.